Pipe bender

ABSTRACT

A PIPE BENDER UTILIZING A CURVED BENDING SHOE OPERATED BY A HYDRAULIC RAM WHICH CAUSES PIVOTAL MOVEMENT OF THE BENDING SHOE WHILE A PIPE IS HELD IN THE SHOE BY A FOLLOW BAR ENGAGING A BACKUP ROLLER, INCLUDING A READILY REMOVABLE MEANS FOR QUICKLY MOUNTING THE BACKUP ROLLER IN DIFFERENT POSITIONS IN THE FORM OF A SHAFT PROVIDING A BEARING SURFACE FOR ROTATABLY SUPPORTING THE ROLLER TOGETHER WITH ECCENTRIC SHAFT END PORTIONS WHICH PREVENT   SHAFT ROTATION DURING BENDING AND MEANS ON THE END PORTIONS TO LOCATE THE SHAFT AXIALLY.

J n. 19,1911 v K. L. HAGEMEYQ 3,555,868

' PIPE BENDER Filed July 18, 1968 4 i Q 5 Z A L-.

United States Patent 3,555,868 PIPE BENDER Kenneth L. Hagemeyer,Rockford, Ill., assignor to Greenlee Bros. & Co., a corporation ofDelaware Filed July 18, 1968, Ser. No. 745,730 Int. Cl. B21d 7/02 US.Cl. 72154 9 Claims ABSTRACT OF THE DISCLOSURE A pipe bender utilizing acurved bending shoe operated by a hydraulic ram which causes pivotalmovement of the bending shoe while a pipe is held in the shoe by afollow bar engaging a backup roller, including a readily removable meansfor quickly mounting the backup roller in different positions in theform of a shaft providing a bearing surface for rotatably supporting theroller together with eccentric shaft end portions which prevent shaftrotation during bending and means on the end portions to locate theshaft axially.

BACKGROUND OF THE INVENTION In the past, it has been conventional inpipe benders, particulaly those of the character mentioned, to provide apair of spaced frame plates or straps between which a bending shoeworks, often under power provided by a hydraulic ram to act against alength of pipe which is opposed by means on the frame arranged in amanner suitable to complement the particular action of the bending shoe,whether it be reciprocable or pivotal or otherwise. In most cases, thebackup means opposing the bending shoe includes a backup roller. Inorder to provide for versatility, provision is often made for using anumber of different bending shoes to accommodate pipes of differentdiameters to produce bends of different degrees. Generally, when thebending shoe is changed, the backup means is also changed. To facilitatethe latter, it is desirable to provide means permitting quick insertionand removal of the backup roller while still retaining the roller inplace in the frame during bending. Further, in those benders utilizingpivoted bending shoes where the opposition is provided by a follow barengaging a backup roller, it is desirable to provide relative rotationbetween parts having relatively large interengaged bearing areas inorder to distribute the rather large loads encountered in a manner toreduce wear and provide long life. Prior art devices known to me havenot provided all the desirable objects referred to above.

SUMMARY OF THE INVENTION In accordance with the present invention, meansis provided for mounting a backup roller in a pipe bender for quickinsertion and removal. In the preferred form illustrated, the mountingmeans is in the form of a cylindrical shaft providing a bearing surfacefor rotatably supporting a backup roller with opposite end portions onthe shaft within the circumference of the shaft but of reduced diameterand eccentric relative to the axis of the shaft. The reduced eccentricopposite end portions are positionable in apertures in the spaced frameplates of the bender corresponding in size to the diameter of the shaftso that insertion and removal are easy and so that on operation of thebender, when the shaft is rotated 180, the eccentric end portions resistfurther rotation, holding the shaft stationary while the roller isforced to rotate on the shaft. In this manner, the wear due to rotationis spread over the relatively large interengaged bearing surfaces of theshaft and the roller, while the relatively smaller areas ofinterengagement bet-ween the shaft end 3,555,868 Patented Jan. 19, 1971portions and the relatively thin frame plates remain stationary for themost part.

Further, bearing in mind that the bender is normally horizontallydisposed with one frame plate above the other, the mounting assemblyincludes a radial pin projecting from one reduced shaft end portionbeyond the circumference of the shaft and beyond the circumference ofthe apertures in all angular positions of the shaft in order to preventthe assembly from passing completely through the frame, thereby tolocate the mounting assembly axially.

Additionally, during operation of the bender, it is desirable to preventthe mounting assembly from climbing in a manner to be dislodged from thelower frame plate, and for such purpose, the opposite reduced endportion is provided with an enlarged terminus concentric with the shaft,to latch beneath the lower frame plate when the shaft is turned from theangular position it assumes during insertion.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects and advantages willbecome apparent from the following detailed description taken inconnection with the accompanying drawings, in which:

FIG. 1 is a plan view of a pipe bender embodying the present inventionwith the backup roller and mounting assembly shown in the positionassumed during insertion and with the remaining parts disposed as tobegin a bending operation;

FIG. 2 is a right side elevational view of the bender illustrated inFIG. 1 with the parts similarly disposed;

FIG. 3 is an enlarged fragmentary sectional View taken through thebackup roller and mounting assembly at about the line 33 of FIG. 1; and

FIG. 4 is a similar view with the mounting shaft rotated 180 from theposition shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT In a preferred embodiment asillustrated in the drawings, a pipe bender includes a pair of generallysimilar spaced parallel frame plates or straps 10 and 11 which areelongate in shape. Adjacent one end, which may be referred to as theinner end, the plates 10 and 11 are widened and bifurcated to provideparallel projections as at 10a and 10b which engage a housing or holder12 having a rectangular outer periphery. In order to secure the strapsends to the housing member 12, pins as at 13 and 14 pass throughapertures in the housing member and the strap ends and are retained inposition by means such as that illustrated at 15 in the nature of acotter pin radially disposed in opposite ends of the mounting pins 13and 14. The member 12 is centrally apertured to support a hydrauliccylinder as at 17 suitably secured in position in the member 12 andhousing a reciprocable ram as at 18. If desired, the ram 18 may bespring urged in a well known manner to a retracted position and drivenoutwardly in a direction to effect the bending operation upon admissionof hydraulic fluid to the opposite end of the cylinder 17 as through afitting 20.

The outer end of the ram is formed to receive a yoke, as at 25, suitablyretained in place as by a pin 26 and shaped with spaced projections 27having aligned apertures to receive a pin 28 removably positionable forholding a bending shoe such as that illustrated at 30 pivotally mountedrelative to the ram and adapted for ready removal to permit substitutionof a bending shoe of different size and/or degree of curvature.

As best seen in FIG. 2, the outer face of the bending shoe 30 isarcuately recessed as shown at 31 to fit a pipe cross section ofpredetermined diameter. As best seen in FIG. 1, the recessed face 31 ofthe bending shoe is curved in a manner to effect some predetermined bendin a pipe of the predetermined diameter. As illustrated, the shoe 30will produce a bend of approximately 45.

In order to effect a bend, a length of pipe, such as that illustrated atP, is positioned in the bending shoe as shown, and held there while thebending shoe is forced to pivot about the attachment to the ram at 28.For such purpose, the ram is driven outwardly, and the bending shoe 30has a U-shaped strap 35 pivotally connected to the bending shoe by a pin36 located off the axis of the ram. The strap 35 embraces the pipe P andhas a working face recessed arcuately, as shown at 37, to fit apredetermined pipe diameter, complementary to the bending shoe. Astraight follow bar 38 adjacent the strap 35 also has a working facearcuately recessed like the face 37 to engage the pipe. The back surfaceof the follow bar 38 engages a backup roller 40 fitted between theoutboard ends of the frame plates and 11 and held in position by amounting assembly 42.

In operation, when fluid under pressure is admitted to the cylinder 17behind the ram 18, the ram is forced outwardly and the bending shoe isforced to pivot at 28. Such movement of the bending shoe acts throughthe strap 35 to pull the pipe along with the bending shoe while the pipeengages the follow bar in turn opposed by the backup roller.

According to the present invention, the mounting assembly '42 includes amain or central shaft portion 44 of cylindrical configuration providingan outer bearing surface engaging the surface of a bore in the roller 40to support the roller. Opposite ends of the shaft 44 are reduced indiameter and eccentric to the axis of the main portion 44 as at 46 and48. The central shaft portion 44 is equal in length to the length of theroller 40 so that the reduced end portions 48 are located at apertures50 and 51 in the frame plates 10 and 11 when the assembly is in properposition. In order to locate the assembly axially and prevent passagethrough the framework, the reduced end portion 46 has a radial pin 52which is long enough to project outwardly beyond the shaft portion 44and the aperture 50 in all angular positions of the assembly. Thus, withthe bender laid horizontally on a floor or the like, with the frameplate 11 on the bottom and the frame plate 10 at the top, the roller 40may be located between the plates 10 and 11 with the bore in the rolleraligned with the apertures 50 and 51 of similar size. With suchrelationship established, the assembly 42 may be simply dropped intoplace by inserting the lower end of the shaft in the aperture 50. Theshaft portion 44 slides through the aperture 50 and into the bore in theroller, as shown in FIG. 3. Since the shaft is of the same size as theroller bore and as the apertures 50 and 51, it is prevented fromdropping too far by contact of the pin 52 with the plate 10'.

During operation, when the ram 18 is extended, the bending shoe pivots,moving the strap 35, the pipe P and the follow bar 38 toward the right,as viewed in FIG. 1. Movement of the follow bar 38 past the roller 40causes rotation of the roller. Initial angular movement of the rolleralso causes angular movement of the assembly 42 since it is free torotate at least a limited amount. After angular movement of about 180,the shaft end portions 46 and 48 bottom or seal in a position where itis easier for the roller 40 to rotate on the shaft 44 than it is for theshaft end portions 46 and 48 to rotate in the apertures 50 and 51, asshown in FIG. 4. At that point, the shaft remains stationary while theroller turns on the shaft. In this way, the relatively large loads aredistributed over the relatively large bearing area of the interengagedsurfaces of the shaft and roller rather than being borne by rotation ofthe shaft ends in the relatively thin plates 50 and 51. In order toprevent the shaft from climbing out of the frame during operation,

and to hold the frame plate ends together, the reduced shaft end portion48 includes an enlarged terminus 54 concentric with shaft 44 and of asimilar size. When the parts are initially assembled, the terminus 54passes entirely through the plate 10, the roller 40, and the plate 11,as shown in FIG. 3. When the shaft rotates the terminus 54 in effectlatches the shaft against movement upwardly.

A bender of the type described usually includes a plurality of differentbending shoes which may be attached to the ram. With the differentbending shoes, there are also different straps as at 35, and differentfollow bars as at 38. With the various different shoes and associatedequipment, the backup roller 40 may be mounted in different positions atvarying distances from the end of the ram 1 8. For such purpose, thereare a plurality of pairs of aligned apertures similar to those shown at50 and 5.1. Four additional pairs of such apertures are shown at 5'5,56, 57 and 58 at varying distances along the frame plates. The mountingassembly 42 is readily disassembled from and mountable in each of thesets of aligned apertures. To remove the mounting assembly, the ram 18is retracted to take the pressure oh? the backup roller whereupon aknurled terminus 59 on the shaft end portion 46 may be grasped to rotatethe shaft 180 from the position of FIG. 4 back to the position of FIG.3. During assembly, a suitable shoe, strap and follow bar are puttogether with the ram retracted to space the parts from the backuproller 40 whatever position the latter is to be moutned in.

I claim:

1. In a pipe bender, a frame, a bending shoe movably mounted on theframe and having a working face formed to engage and bend a length ofpipe on movement of the shoe, meansv on the frame to engage the pipe in0pp0sition to the bending shoe including a backup roller, means formounting the roller for quick insertion and removal including a shafthaving a bearing surface rotatably supporting the roller and eccentricopposite end portions positionable in the frame to hold the shaftstationary while the roller turns on the shaft, said frame beingconstructed to permit free rotation of the shaft to a position where theaxis of the shaft is displaced from the axis of the eccentric portionsaway from the bending shoe, and means for working the bending shoe.

2. In a pipe bender, a frame, a bending shoe pivoted on the frame havinga working face formed to receive a length of pipe, a follow barcomplementary to the bending shoe for holding the pipe, a strap on thebending shoe for holding the pipe on the shoe, a backup roller disposedbehind the follow bar, means for mounting the roller comprising acylindrical shaft providing a bearing surface rotatably receiving theroller, and eccentric opposite end portions of the shaft positionable inrecesses in the frame so that on angular movement of the shaft theeccentric end portions seat in the recesses to retain the shaftstationary while the roller turns on the shaft, said frame beingconstructed to permit free rotation of the shaft to a position where theaxis of the shaft is displaced from the axis of the eccentric portionsaway from the bending shoe, and means for pivoting the bending shoe.

3-. A combination as defined in claim 2 including a radial projection onone shaft end portion to engage the frame and locate the shaftlongitudinally.

4. In a pipe bender,

a frame,

a reciprocable ram on the frame,

a bending shoe pivoted on the ram having a working face curvedlengthwise and recessed transversely to receive a length of pipe,

a follow bar recessed transversely complementary to the bending shoe forholding the pipe,

a strap on the bending shoe for holding the pipe on the shoe,

a backu roller disposed behind the follow bar in opposition to the ram,and

a mounting for the roller comprising a cylindrical shaft providing abearing surface positionable in the roller, and reduced eccentricopposite end portions on the shaft positionable in apertures in theframe corresponding in size to the shaft to support the shaft, so thaton angular movement of the shaft the eccentric end portions seat toretain the shaft stationary while the roller rotates on the shaft.

5. A combination as defined in claim 4 including a radial projection onone shaft end portion projecting outwardly beyond the shaft and therecesses in all positions of the shaft to locate the shaft axially.

6. A combination as defined in claim 4 including a radial projection onone shaft end portion having a terminus within the circumference of theshaft bearing surface to pass through the roller and the recesses in oneangular position and to extend beyond the adjacent recess when angularlyrotated to seat.

7. A pipe bender comprising,

a frame including a pair of spaced parallel plates,

a reciprocable ram on the frame between the plates,

a removable bending shoe pivoted on the ram having a working face curvedlengthwise and recessed transversely to receive a length of pipe,

a follow bar recessed transversely complementary to the bending shoe forholding the pipe,

a removable strap on the bending shoe off the axis of the ram forholding the pipe on the shoe,

a backup roller disposed behind the follow bar in opposition to the ram,and

means for removably mounting the roller comprising means providing aplurality of pairs of aligned apertures in the spaced frame plates,

a cylindrical shaft corresponding in size to the apertures providing abearing surface positionable in the roller,

reduced eccentric opposite end portions on the shaft positionable in theapertures in the frame plates so that on angular movement of the shaftthe eccentric end portions seat to retain the shaft stationary while theroller rotates on the shaft, and

means to locate the shaft axially.

8. A pipe bender as defined in claim 7 wherein the means to locate theshaft axially includes a transverse pin in one shaft end portionprojecting outwardly beyonfd the shaft and the apertures in allpositions of the sha t.

9. A pipe bender as defined in claim 8 wherein the means to locate theshaft axially includes an enlarged terminus on the other shaft endportion concentric with the shaft to pass through the roller andapertures in one angular position and to latch behind one frame platewhen angularly rotated to seat.

References Cited UNITED STATES PATENTS 2,375,310 5/1945 Mandl 72-1S4FOREIGN PATENTS 1,210,700 10/1959 France 72-219 RIOHARD J HERBST,Primary Examiner US. Cl. X.R, 72-219

